Mutagenic Action of Ethyl Methanesulfonate in Maize

Pollen of corn plants carrying three closely linked genes (alpha beta Sh(2)) on chromosome 3 were treated by ethyl methanesulfonate in order to determine the nature of genetic changes produced. In this genetic material the loss of the beta gene alone represents a discrete genetic change, possibly a point mutation, while the loss of two or more markers represents chromosome aberrations. Ethyl methanesulfonate, x-rays, and ultraviolet light all induced numerous chromosome aberrations, but only ultraviolet light and probably ethyl methanesulfonate induced discrete genetic changes.